a) Field of the Invention
The present invention is concerned with a multifunctional surgical instrument for use in carrying out laparoscopic surgery.
b) Brief Description of the Prior Art
Laparoscopic surgery is a relatively new operating technique that has been developed to carry out percutaneous surgery and more especially cholecystectomy (gallbladder removal) also it could be used in gynecology, meurosurgery and urology.
This technique is much less invasive than a conventional surgery and thus may be carried out using only sedimentation and a local anaesthetic. It involves puncturing the abdominal wall and inducing a pneumoperitoneum to distend the abdomen. A cannula of about 1 cm in diameter is inserted into the puncture and used as a "guiding member" through which one or more surgical instruments may be inserted and guided with great accuracy towards, the body part requiring surgery. Such instruments may include an endoscope (laparoscope), a biopsy needle, a clip applier, microscissors or forceps, a fiber-optic rod connected to a laser source for hemostatic cutting or coagulation, a set of electrodes connected to a generator for electrocautery, etc. . . If desired, one or more smaller cannulas may be inserted into the 1 cm cannula to work with two or more instruments.
Following the surgery, the puncture may be closed in a very simple manner, using a sterile adhesive strip to do so. This permits to reduce to a minimum extent the patient's stay at the hospital and the period for his or her recovery and resumption of normal activity. This also permits to reduce the post-operation scar.
During surgery, it is often required to irrigate with a flushing liquid, i.e. a saline, or to suction the internal body cavity which may be, for example, the liver bed region or the gallbladder, without having to stop the surgical step that is being carried out. It is also required to evacuate stones or blood clots from the cavity.
To do so, surgical instruments have been devised, which are in the form of a rigid hollow tube also called "trocar", which is connectable to a source of vacuum and a source of flushing liquid. A set of valves known as "trumpet valves" are rigidly mounted at the rear end of the tube and used to sequentially connect the same to both of these sources, respectively, for suction of physiological matter or irrigation purpose.
Recently, it has been suggested to incorporate a pair of bipolar electrodes fed by electrically insulated wires connectable to an electrosurgical generator at the front end of a suction and irrigation tube of the above mentioned type, to make it also useful for coagulating and cauterizing as need may be, thereby increasing the versatility of the instrument while simultaneously reducing the number of instruments to be inserted at the very same type in the cannula (see Canadian laid-open patent application No. 2,037,139 published on Oct. 31, 1991 to EVEREST MEDICAL CORP.) It has also been suggested to mount such a suction and irrigation tube in a detachable manner onto a pistol-grip shaped holder incorporating the required set of valves so that these valves be actuable with a finger like a pistol trigger, so as to facilitate manipulation of the instrument in use (see Canadian laid-open patent application No. 2,042,456 published on Nov. 26, 1991 to Edward H. PHILLIPS). This pistol-shaped instrument which may incorporate or not a set of electrodes for electrocautery or a laser optic fiber bundle for laser surgery techniques, is much more handy than those used so far. However, the valve assembly in the holder is not readily accessible and easy to change whenever required. Moreover, the tube is attached to the holder by means of screws, thereby making an interchange rather difficult to carry out during an operation.